[Code of Federal Regulations] [Title 40, Volume 31] [Revised as of July 1, 2006] From the U.S. Government Printing Office via GPO Access [CITE: 40CFR1039.510] [Page 510] TITLE 40--PROTECTION OF ENVIRONMENT CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PART 1039_CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION-IGNITION ENGINES--Table of Contents Subpart F_Test Procedures Sec. 1039.510 Which duty cycles do I use for transient testing? (a) Measure emissions by testing the engine on a dynamometer with one of the following transient duty cycles to determine whether it meets the transient emission standards in Sec. 1039.101(a): (1) For variable-speed engines, use the transient duty cycle described in Appendix VI of this part. (2) [Reserved] (b) The transient test sequence consists of an initial run through the transient duty cycle from a cold start, 20 minutes with no engine operation, then a final run through the same transient duty cycle. Start sampling emissions immediately after you start the engine. Calculate the official transient emission result from the following equation: Official transient emission result = 0.05 x cold-start emission rate + 0.95 x hot-start emission rate. [69 FR 39213, June 29, 2004, as amended at 70 FR 40463, July 13, 2005]